An open window, a sleep tracker, and an evening shower

Adams and Franklin disagree over a window

In his autobiography, John Adams recalled a night in New Brunswick during a September 1776 diplomatic journey. The crowded inn had only one bed available for him and Benjamin Franklin. Their small room had one window. Adams, worried about night air, shut it. Franklin wanted it open and offered to explain his theory of colds. Adams reopened the window, got into bed, and eventually fell asleep during Franklin’s explanation. ¹

Adams wrote this account retrospectively; it is preserved by the National Archives. It records the men’s disagreement but cannot establish whether the open window affected their sleep.

The patient whose tracker disagreed

A much later disagreement appears in Rush University’s account of a 2017 clinical case series. A patient identified as Ms. B, aged 27, felt unrefreshed and believed her tracker showed poor sleep. Laboratory testing recorded substantial deep sleep, yet she remained concerned about the device’s estimate. The university’s report describes her questioning how the two could disagree. ²

The clinicians reported the patient anonymously. Their account does not describe a final resolution.

A clinical case is selected because it raises a concern. It cannot tell us how common that concern is among people who use sleep trackers.

The researcher who changed his shower time

In a 2025 interview with TIME, sleep researcher Shahab Haghayegh described moving his shower from morning to evening while trying to shift his bedtime earlier. He reported that the change helped and that his experience prompted research into warm bathing and sleep. ³

Changes to bedtime, expectations, other habits, and ordinary variation could also have contributed to the improvement he noticed.

His account leads to a question the published research can address: under what conditions does warm bathing affect sleep?

What warm-bathing studies found

Haghayegh and colleagues’ 2019 review identified seventeen relevant studies of warm water-based heating before bedtime, thirteen suitable for quantitative synthesis. The results supported improvements in some sleep outcomes, with benefits for falling asleep when bathing occurred one to two hours before bed. The authors also emphasized limitations in the amount of research and uncertainty about the optimal details. ⁴

The review covers multiple studies and measured sleep outcomes, giving it a firmer basis than one person’s recollection. It still does not establish that an evening shower treats chronic insomnia.

Applying an idea from someone else’s experience

When another person’s night resembles yours, pause at the point of recognition. What exactly is similar: the shared room, the worry, the schedule, or the intervention? What is different? If you try a modest change, decide what improvement would mean and observe more than one night. Keep the conditions visible rather than crediting every change to the most memorable new habit.

For practical detail, read the bedroom comfort guide for bathing research and adjustments to heat, light, and bedding, or the sleep-tracker guide for measurement limits and signs that need assessment.